Sen. Shelley Moore Capito Thursday sided with Vice President Mike Pence in his war of words against fellow Sen. Joe Manchin, saying her fellow West Virginian had disappointed Pence with his vote against tax cuts.

"I think that Sen. Manchin may have intimated to the vice president that he was on board with tax cuts," the West Virginia Republican told Fox News' "America's Newsroom," adding that Republicans were talking about expanding businesses and giving bonuses for workers in their state with the reform legislation.

On Wednesday, Pence slammed Manchin, a Democrat, on Twitter for voting against the tax reform package and for being against a series of administration policies. His tweets sparked a strong rebuke from Manchin, with the moderate West Virginia lawmaker responding that he'd worked in a bipartisan way to stop the recent government shutdown, and that Pence's attack "are exactly why Washington sucks."

Capito on Thursday also rejects Manchin's comment about Washington.

"We volunteer to come here, we ask people to send us to Washington and we're serving in the greatest deliberative body in the most powerful nation," said Capito. "I wouldn't use that terminology to see the honor I have to be a United States senator."

The tax cuts have meant optimism and an economic boost nationwide, the senator said, including in her state.

"Here in West Virginia we're seeing it everywhere, with bonuses and expansions," she said. "You can't deny this is a great thing, and when people get their checks and they have more on the bottom line of their checks, the American people are going to realize this was something that was long waited for and the Democrats will be held accountable for the way they voted."

Sen. Shelley Moore Capito Thursday sided with Vice President Mike Pence in his war of words against fellow Sen. Joe Manchin, saying her fellow West Virginian had disappointed Pence with his vote against tax cuts.